Laboratory research facility for testing hydrodynamic thrust bearings

Abstract

A research facility has been designed and manufactured to study performance characteristics of industrial hydrodynamic thrust bearings. The facility includes a test rig containing two identical tilting pad thrust bearings operating against separate collars. A shaft supported by two journal bearings is driven by a 143kW variable-speed d.c. motor. The bearings are tested in a balanced pair to accommodate the substantial axial force generated by hydraulic cylinders. Bearing instrumentation encompasses a distribution of thermocouples, pressure transducers and oil-film thickness sensors of eddy current type. Two piezoelectric transducers for pressure profile measurements and three thermistors are mounted in one of the shaft collars. Additional instrumentation includes thermocouples, pressure sensors, flowmeters, a load cell and inductive sensors. Signals from all sensors are logged by a personal computer-based high-speed data acquisition system that acquires the measured data, conditions them and presents the results on line. Power losses are obtained by monitoring bearing friction torque and by the calorimetric technique. A detailed description of the research facility is provided together with some representative results of equalizing tilting pad thrust bearing performance obtained for the steady state and transient operating conditions.